Sharpening arm



FIG. 1 is a perspective view of a sharpening arm, showing our new design;

FIG. 2 is a right-side view thereof;

FIG. 3 is a left-side view thereof;

FIG. 4 is a front view thereof;

FIG. 5 is a rear view thereof;

FIG. 6 is a top view thereof;

FIG. 7 is a bottom view thereof; and,

FIG. 8 is a front view of a sharpening arm in association with a stone holder and chainsaw.

The dashed lines are included for illustrating environmental structure and form no part of the claimed design. 

We claim an ornamental design for a sharpening arm, as shown and described. 